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View Full Version : crossovers / what's the correct way of crossing



retro soulman
05-13-2018, 05:34 AM
Hello. I just need your opinion about this :)
My system (JBL 4530 , d140 , 2390 , 2445 , 2402) is a 2 way active via a BSS 310 crossover & a passive crossover just for the 2402 tweeter.
So months ago i purchase a pair of 3105 crossovers to try for my 2445J & 2402. I try it like it was and after recap. The result wasnt that nice... i loose much of the detail from my horn drivers and loose some space and image also (because of loosing detail of course) ...
i believe that just adding a passive crossover on your tweeters , without cutting the horn driver in its upper freq ( the freq that the tweeter starts acting ) is much better. What do you think about it? best regards

Robh3606
05-14-2018, 07:09 PM
Well if you don't like it? As far as why well you are really rolling off the 2445 and if you consider the power response over all you are losing siginificant energy from the 2445 even under 10k. The actual crossover point is lower than you might expect. 5K with -12.5 Db of roll off @ 10K on the LF driver in this case the 2445

Take a look at this


http://www.jblproservice.com/pdf/Network%20Schematics/3105%20Network.pdf

Rob

retro soulman
05-14-2018, 11:21 PM
Well if you don't like it? As far as why well you are really rolling off the 2445 and if you consider the power response over all you are losing siginificant energy from the 2445 even under 10k. The actual crossover point is lower than you might expect. 5K with -12.5 Db of roll off @ 10K on the LF driver in this case the 2445

Take a look at this


http://www.jblproservice.com/pdf/Network%20Schematics/3105%20Network.pdf

Rob

The sound without the 3105 is significal better, but with the 3105 is more solid, coming in "one piece" from the speakers. I recap the crossovers but the only improvment i hear was very limited

Ian Mackenzie
05-15-2018, 12:08 AM
Hello. I just need your opinion about this :)
My system (JBL 4530 , d140 , 2390 , 2445 , 2402) is a 2 way active via a BSS 310 crossover & a passive crossover just for the 2402 tweeter.
So months ago i purchase a pair of 3105 crossovers to try for my 2445J & 2402. I try it like it was and after recap. The result wasnt that nice... i loose much of the detail from my horn drivers and loose some space and image also (because of loosing detail of course) ...
i believe that just adding a passive crossover on your tweeters , without cutting the horn driver in its upper freq ( the freq that the tweeter starts acting ) is much better. What do you think about it? best regards

I know what you mean.

I suggest you leave the horn full range for now and experiment with a much higher crossover point for the 2402 like 15-20 khertz

I have edited this post with some options:

Option A
Buy yourself an 8 ohm L pad and a selection of polypropylene capacitors 0.5 u, 1 u, 1.5 u, 2 u from Parts Express. Wire the cap in series with the input of the L pad. The output of the Lpad connects to the 2402 just like the 3105 network but leave out the inductor for now.

Then try the different capacitor values until you get the 'air' you are looking for and adjust the level.(or put the caps in parallel to get the right result).

Option B
Alternatively you could experiment with this actively in mono by daisy chaining of both channels of the BSS active crossover so you have a mono situation and adjust the BSS until you get the desired result with the 2402. That would give you flexibility to design what works for you and then make a passive network to emulate the active settings later on.

There is no real rule book on this particular area. Just listen. Don’t over engineer the idea before you listen. For example Jbl’s approach in this situation varies in the HiFi offerings. Some systems let the horn runout full range. Others have have a clearly defined pass band. The other variable is individuals hearing at this end of the frequency spectrum varies so it’s about what works for you.

You might also experiment with moving the 2402 around in different locations. Again try a few options and listen.

I hope this helps.

grumpy
05-15-2018, 06:59 AM
Those are some killa-hertz ;)

Ian Mackenzie
05-15-2018, 11:44 AM
Not at our age...Lol

Okay l just looked at the https://bssaudio.com/en/products/fds-310

The max sweepable crossover point is 9 khertz.
I would still try out the 3 way active mono option above and listen to the result. It might be good or it might be crap or just different compared to the passive 3105.